Factorize the following quadratic polynomials by splitting the middle term:

1. [tex]x^2 + 10x + 16[/tex]
2. [tex]x^2 - 12x + 20[/tex]
3. [tex]6x^2 + 19x + 10[/tex]
4. [tex]x^2 + 14x + 33[/tex]
5. [tex]x^2 - 3x - 40[/tex]
6. [tex]6x^2 + 7x - 20[/tex]
7. [tex]15x^2 + 7x - 2[/tex]
8. [tex]x^2 - 4x - 77[/tex]
9. [tex]x^2 + 2x - 143[/tex]
10. [tex]12x^2 + 23x + 5[/tex]